Apparatus for closing bag tops and the like



1966 w. E. MACDONALD 3,269,092

APPARATUS FOR CLOSING BAG TOPS AND THE LIKE Filed Aug. 23, 1965 2 Sheets-Sheet 1 Aug. 30, 1966 w. E MACDONALD 3,

APPARATUS FOR CLOSING BAG TOPS AND THE LIKE 2 Sheets-Sheet 2 Filed Aug. 23, 1963 United States Patent Oflfice 3,269,692 Patented August 30, 1965 3,269,092 APPARATUS 1 R CLGSING BAG TGPS AND THE LIKE Warren E. Macdonald, West Harrington, ILL, assignor to St. Regis Paper Company, New York, N.Y., a corporation of New York Filed Aug. 23, 1963, Ser. No. 304,042 Claims. (Cl. 53371) This invention relates to apparatus for closing packages and is more particularly adapted, among other possible uses, for assisting in the folding of the flaps which form the end closures, such as for paper bags and for compressing the ends of such packages when filled and while same are being closed. By way of example the invention will be described as applied to bag closures, although it will be understood in various of its aspects the invention is applicable to other package closures.

Heretofore it has been common practice to provide equipment for folding and closing the flaps of paper bags, including various forms of plow-like means for finally folding the end closure and guiding the closure flaps down into proper places for sealing. While such equipment operates successfully under many circumstances, the use of such plow-like means presents a frictional drag against the closures along predetermined lines and does not readily accommodate itself to varying heights and may sometimes form imperfect closures by reason of the shifting of the contents within the top of the bag, if there are contents which resist proper formation of the closure.

In practice, a means is used preceding the apparatus of the present invention for first folding in the so-calle-d corner flaps at the end of the filled bag, and then engaging the side flaps with the corner flaps as folded in therebetween, by guides or suitable means for pressing the side flaps together, thereby establishing a closure which still has portions of the flaps upstanding and ex tending longitudinally along the center line of the bag end as the bag is conveyed along the direction of such line. Then, in accordance with the invention, such upstanding closure portion is engaged by a disk which is so mounted as to be freely rotatable about a shaft positioned at an angle such that the bag closure portions will engage the higher portions on the undersurface of the disk and, as the disk rotates by reason of engagement with the bag closure, the latter becomes tilted over and flattened down for proper sealing relation to the end of the bag. Such disk also preferably is so mounted on its shaft that it may float up or down along such shaft, depending on the height of the filled bag and so as to apply pressure to the top of the filled bag, corresponding to the weight of the disk assembly, and for more or less yieldably pressing the end of the filled bag into compact condition, even though the contents within the top of the bag may not always be in a predetermined position, or may shift somewhat.

Various further and more specific objects, features and advantages of the invention will appear from the description given below, taken in connection with the accompanying drawings, illustrating by way of example a preferred form of the invention.

In the drawings:

FIG. 1 is a side elevational view of a preferred embodiment of apparatus involving the invention as applied by way of example to the closing of bags;

FIG. 2 is a plan view of same;

FIG. 3 is a sectional view taken substantially along line 3-3 of FIG. 1;

FIG. 3A is a side view of the top of a bag after the closure portions have been folded down to closed positions by the action of the rotatable disk;

FIG. 4 is a horizontal sectional view taken substantially along line 44 of FIG. 5; and

FIG. 5 is a side View, partly in section, of the rotatable disk and associated parts of the apparatus.

Referring now to the drawings in further detail, there is schematically shown in FIG. 1 suitable conveying and guiding means 10 and 11 which may be of known type and as adapted for conveying and guiding a succession of filled bags as at 12 along through the appaartus for folding down the top closure flaps of the bags. The bags may be spaced apart as by spacer members 13. As indicated at the right hand end of FIGS. 1 and 2, the bag 12 as here shown has more or less upstanding so-called corner flaps as at 14, 15, and side flaps as at 16, 17. At the station here shown, suitable finger means of known form as at 18, 19 are pivotally mounted on rotatable supports as at 20, in such manner that when the fingers are turned in the direction of the arrows indicated in FIG. 1, the corner flaps 14, 15 will be folded in against the top of the bag. Then, as the bags advance, the upstanding portions of the flaps may pass between suitable guide means as at 21, and thence in known manner through the nip of pressure rollers as at 22, 23.

Thereafter the bags are conveyed to pass under a rotatable disk 25, mounted, as shown in FIG. 1, to be freely rotatable about a supporting shaft 26, the axis of which is positioned at a downwardly, rearwardly, and sidewardly directed and adjustable angle as compared with the path of travel of the bags. For example the disk may be in a plane tilted about a line indicated at in FIG. 2. Thus the remaining upstanding portions of the bag closure flaps, as indicated at 27, will first engage the undersurtace of the more elevated side of the disk 25, and, as will be apparent from FIGS. 1 and 2, as the bag closure portions advance in engagement with the undersurface of the disk and along one side of the axis thereof, the flap portions will gradually be tilted and turned down about fold lines as at 28, with the consequence that, as the bag closures pass beyond the lowermost side 29 of the disk, the flap portions will be securely flattened down against the end of the bag, as indicated at 30 and as more clearly shown in FIG. 3A.

Meanwhile, since the disk is freely rotatable about its shaft, its portions which engage the bag closure portions will not tend to apply any very substantial frictional drag thereto, but instead the undersurface of the disk will be engaged and the disk caused to turn or continue turning about its axis, While the end of the package is folded over due to the inclination of the disk. Furthermore, since the disk is free to float, that is, free to shift in its position up and down the shaft 26, its weight will tend to urge the disk downwardly against the bag tops, thereby applying suflicient pressure thereto more or less to compact same and the contents, while the disk is still free to rise if it is engaged by a bag somewhat higher than the others, or a bag wherein the contents may have shifted to one side within the bag top. Thus a simple effective means is provided for more or less yieldably compressing the bag top, without applying any substantial frictional dragging effect.

By way of further explanation of the operation of the disk, as may be seen from FIG. 2, when the upstanding bag closure portions 27 initially engage the underside of the periphery of the disk 25, such engagement will be in a direction along the axis of the conveyor which is positioned to one side of the axis of the disk. As a consequence, such engagement with a segmental portion of the disk will cause the disk to turn in the direction indicated by the arrow, and thus determine that the upstanding flap portions will begin to be folded over in the general direction indicated by the arrow. Then, as the bag closure proceeds to engage further segmental portions of the undersurface of the disk, the closure portions will be increasingly folded over, and, due to the portions of the disk nearer the axis thereof being at a lower level, same will cause pressure to be applied as the bag closure is increasingly flattened down and finally, as the bag closure leaves the disk at a region where its periphery is at its lowest, the bag flaps will accordingly be fully flattened down under pressure. Yet here the direction of the forces on the disk will be such that the disk continues to rotate with inconsequential dragging friction against the top of the bag.

It is also notable that as the bag travels in a substantially straight line as it passes the face of the disk, the flap hinge line passes closer to the center line of the disk than does the portion of the bag against which the formed flaps are folded and pressed. Due to this arrangement the portion of the face of the disk in contact With the edge of the folded formed flaps is at a greater radius from the axis of the disk than the portion of the disk in contact with hinge point of the folded formed flaps. The greater radius provides a faster surface speed at the portion of the disk in contact with the edge of the flaps than the portion of the disk in contact with the hinge point of the flaps. The higher speed at edge of the folded flaps in combination with, and resulting from the rotary movement of the disk surface provides a sweeping, wiping motion to fold the formed flaps over onto the package end. This sweeping, wiping motion provides a square, straight folded package end. Previous known common methods of folding, such as with folding plows, cause the folded flaps to be folded out-of-square at slight backward angular positions due to frictional drag in the plows and geometrically unavoidable distortion in folding the flaps. The sweeping, wiping action of the angled, rotating disk surface allows the distortion to take place in the initial phases of folding and then corrects the condition before final pressing occurs.

As best shown in FIGS. 4 and 5, the disk 25 may be bolted to a flanged sleeve as at 31, which in turn is vertically slidable up and down along the shaft 26. Suitable means, such as a collar 32, may be affixed to the lower end of the shaft, if desired, to limit downward sliding of the disk at times when no bags are positioned thereunder.

The upper end of the shaft 26 may be clamped within a collar means as at 33, having an aperture 34, the axis of which is adjustably positioned at the pro-per angle for holding the shaft in its downwardly, rearwardly, and sidewardly directed angular position, as shown in the drawings. The collar means 33 may be received within an aperture 35 within a frame member 36. The upper end of the aperture 35 may be closed as by a plate 37, for holding the collar 33 down in place against the shoulder 39 within aperture 35. The sideward angle can be set by rotating the collar to the desired position before clamping in place by the plate 37. The supporting means 36 is preferably so mounted as to be vertically adjustable, thereby to permit vertical adjustment of the general position of the disk 35, to accommodate packages of different normal heights. Such vertical adjustment may comprise a suitably mounted threaded rod 37 and a guide rod as at 38, both passing up through the frame or support 36. A worm gear 39 may threadedly engage the shaft 37, and this gear may be operated by rotating a worm 40 by means of handle 41, thereby raising or lowering the assembly as desired.

Although a certain particular embodiment of the invention is herein disclosed for purposes of explanation, further modifications thereof, after study of this specification, will be apparent to those skilled in the art to which the invention pertains. Reference should accordingly be had to the appended claims in determining the scope of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. Apparatus for folding over upstanding closure portions on packages, comprising in combination: means for ll conveying the packages along a predetermined line with the closure portions upstanding therefrom; a disk mounted to be rotatable in a position whereby the closure means on the conveyed packages engage along incremental portions on the undersurface of the disk, said disk being mounted on a tilted axis such that said closure means first engage the higher portions of the undersurface of the disk and cause rotation thereof while the closure portions gradually are engaged by progressively lower portions of the disk and become folded over and pressed down against the packages as same pass from engagement with the lower portion of the disk, said disk being substantially freely rotatable about its axis by reason of engagement with said closure means on the packages, and the disk being substantially free to move up and down along its axis depending upon the supporting pressure which the closure means exert thereon.

2. Apparatus for folding over upstanding closure portions on packages, comprising in combination: means for conveying the packages along a predetermined line of travel with closure portions upstanding therefrom; and a rotatable disk mounted in a position whereby the closure portions on the conveyed packages engage along one side of the undersurface areas of the disk, said disk being mounted on an axis so tilted at its lower portions rearwardly with respect to the direction of travel of the packages that said closure portions first engage higher areas on the undersurface of the disk and gradually become engaged by progressively lower areas on the undersurface of the disk and thereby become folded over as the packages advance.

3. Apparatus for folding over closure portions on packages, comprising in combination: means for conveying the packages along a predetermined line of travel with the closure portions protruding therefrom; and a rotatable disk mounted along side said line of travel in a position whereby undersurface areas at one side thereof engage said closure portions, said disk being positioned in a tilted plane at an angle to said line of travel such that the closure portions first are engaged by a relatively high area of the undersurface of the disk and are subsequently engaged by lower areas of such undersurface as the packages are advanced past said disk.

4. In apparatus for closing filled bags having upstanding closure flaps including pairs of opposed side flaps and corner flaps: means for conveying the filled bags along a predetermined path of travel; means for folding in the corner flaps; means for then guiding the side flaps and compressing same together with portions of the folded-in corner flaps therebetween, while leaving portions of the flaps upstanding in a plane extending along said line of travel; and a rotatable disk mounted in a position whereby said upstanding portions then engage along one side of the undersurface of the disk, the disk being mounted on an axis so tilted with respect to said line of travel that said upstanding portions first engage higher portions of the undersurface of the disk and gradually become engaged by lower portions of the disk and become folded over as the packages advance.

5. Apparatus in accordance with the foregoing claim 4 and in which said disk is substantially freely rotatably about its axis by reason of engagement with the closure means and the disk is also free to move up and down along its axis depending upon the supporting pressure which the closure means exert thereon.

FOREIGN PATENTS 1,248,104 10/1960 France.

747,574 4/1956 Great Britain.

TRAVIS S. MCGEHEE, Primary Examiner. 

2. APPARATUS FOR FOLDING OVER UPSTANDING CLOSURE PORTIONS ON PACKAGES, COMPRISING IN COMBINATION: MEANS FOR CONVEYING THE PACKAGES ALONG A PREDETERMINED LINE OF TRAVEL WITH CLOSURE PORTIONS UPSTANDING THEREFROM; AND A ROTATABLE DISK MOUNTED IN A POSITION WHEREBY THE CLOSURE PORTIONS ON THE CONVEYED PACKAGES ENGAGE ALONG ONE SIDE OF THE UNDERSURFACE AREAS OF THE DISK, SAID DISK BEING MOUNTED ON AN AXIS SO TILTED AT ITS LOWER PORTIONS REARWARDLY WITH RESPECT TO THE DIRETION OF TRAVEL OF THE PACKAGES THAT SAID CLOSURE PORTIONS FIRST ENGAGE HIGHER AREAS ON THE UNDERSURFACE OF THE DISK AND GRADUALLY BECOME ENGAGED BY PROGRESSIVELY LOWER AREAS ON THE UNDERSURFACE OF THE DISK AND THEREBY BECOME FOLDED OVER AS THE PACKAGES ADVANCE. 